Question

我尝试使用JAVA实现神经网络反向传播，我已经对其进行了编码，但结果却是无法解决的。错误正在减慢太慢。以下是火车结果的示例：

epoch:1  current error:0.5051166876846451

epoch:2  current error:0.4982484527652138

epoch:3  current error:0.4965995467118879

epoch:4  current error:0.49585659139683363

epoch:5  current error:0.4953426236386938

epoch:6  current error:0.4948766985413233

epoch:7  current error:0.49441754405152294

epoch:8  current error:0.4939551661406868

epoch:9  current error:0.49348601614718984

epoch:10 current error:0.4930078119902486

epoch:11 current error:0.49251846766886453

基于此，我开始怀疑我的代码及其算法。使用的激活函数是sigmoid。以下是培训的示例代码。

public void learning(int epoch,double learningRateTemp,double desiredErrorTemp,DataSet ds,double momentum){
    int processEpoch=0;
    double sumSquaredError=0;
    DataSetRow dsr;
    Connector conTemp;
    double sumError=0;
    double errorInformation=0;
    double activationValue;
    double partialDerivative;

    do{
        processEpoch++;
        sumSquaredError=0;
        System.out.println("epoch:"+processEpoch);
        //data training set
        for(int a=0;a<ds.countRows();a++){
            dsr=ds.getSpecificRow(a);
            sumError=0;
            double[]input=dsr.getInput();
            double[]output=dsr.getdesiredOutput();
            double sumDeltaInput=0;
            double weightTempValue=0;
            //forward calculation
            this.forwardCalculation(input);               
            //backpropagateofError
            //for output unit

            for(int k=0;k<NeuralLayers[totalLayer-1].getTotalNode();k++){
                activationValue=NeuralLayers[totalLayer-1].getNeuron(k).getValue();
                partialDerivative=(activationValue)*(1-activationValue);
                Neuron Temp=NeuralLayers[totalLayer-1].getNeuron(k);
                errorInformation=(output[k]-Temp.getValue())*partialDerivative;
                Temp.SetErrorInformationTerm(errorInformation);
                sumError+=Math.pow((output[k]-Temp.getValue()),2);
                NeuralLayers[totalLayer-1].setNeuron(k, Temp);
            }
            //end of output unit
             //for hidden Unit
            for(int l=totalLayer-2;l>0;l--){
                for(int j=1;j<NeuralLayers[l].getTotalNode();j++){
                     sumDeltaInput=0;
                     for(int k=0;k<NeuralLayers[l+1].getTotalNode();k++){                                
                       conTemp=NeuralLayers[l+1].getConnector(k, j);
                       if(conTemp.getStatusFrom()==false){
                              weightTempValue=conTemp.getWeight().getValue();
                              sumDeltaInput+=(NeuralLayers[l+1].getNeuron(k).GetErrorInformationTerm()*weightTempValue);
                            }
                        }
                     activationValue=NeuralLayers[l].getNeuron(j).getValue();
                     partialDerivative=(activationValue)*(1-activationValue);
                     errorInformation= sumDeltaInput*partialDerivative;                
                     Neuron neuTemp=NeuralLayers[l].getNeuron(j);
                     neuTemp.SetErrorInformationTerm(errorInformation);
                     NeuralLayers[l].setNeuron(j, neuTemp);
                     }
                }
            updateWeight(learningRateTemp,momentum);
            sumSquaredError+=sumError;            
            }       
    sumSquaredError/=(double)(ds.countRows()*NeuralLayers[totalLayer-1].getTotalNode());
    sumSquaredError=Math.sqrt(sumSquaredError);
    System.out.println("current error:"+sumSquaredError);
    } while(processEpoch<epoch && sumSquaredError>desiredErrorTemp);
}

}

用于正向计算

private void forwardCalculation(double[] inputValue){
        Connector Contemp;
        double SumNodeWeight=0;
        int start=1;
        int count=0;
        setNodeValue(inputValue,0);
        do{
            count++;
            if("output".equals(NeuralLayers[count].statusLayer))
                     start=0;
                else start=1;
           //get sum of all input  
            for(int j=start;j<NeuralLayers[count].getTotalNode();j++){
                for(int i=0;i<NeuralLayers[count].sizeConnector(j);i++){
                    Contemp=NeuralLayers[count].getConnector(j, i);
                    SumNodeWeight+=Contemp.getCombinedweightInput();
                }
                SumNodeWeight=(1/(1+Math.exp(-SumNodeWeight)));
                NeuralLayers[count].setNeuronValue(j, SumNodeWeight); 
                SumNodeWeight=0;
            }
    }while(!"output".equals(NeuralLayers[count].statusLayer));
 }

并更新权重

private void updateWeight(double learningRateTemp,double momentum){
    double newWeight;
    double errorInformation;
    Connector conTemp;
    for(int LayerPosition=totalLayer-1;LayerPosition>0;LayerPosition--){
        for(int node=1;node<NeuralLayers[LayerPosition].getTotalNode();node++){
            errorInformation=NeuralLayers[LayerPosition].getNeuron(node).GetErrorInformationTerm();
                //for bias weight
                newWeight=learningRateTemp*errorInformation;
                conTemp=NeuralLayers[LayerPosition].getConnector(node, 0);
                conTemp.updateWeight(newWeight,false,0);
                NeuralLayers[LayerPosition].updateConnector(conTemp, node, 0);
                /////////////////////
                //for other node weight
                for(int From=1;From<NeuralLayers[LayerPosition].sizeConnector(node);From++){
                    conTemp=NeuralLayers[LayerPosition].getConnector(node, From);
                    double weightCorrection=learningRateTemp*errorInformation*NeuralLayers[LayerPosition-1].getNeuron(From).getValue();
                    conTemp.updateWeight(weightCorrection,true,momentum);
                    NeuralLayers[LayerPosition].updateConnector(conTemp,node,From);
                }
        }
    }
}

我正走在正确的轨道上吗？我已经在几天内搜索了这些bug，但它仍然没有。我计算误差的公式是否正确？非常感谢你！

Answer 1

嗯，我不是这方面的专家，也不是Java编程，但它可能会影响，你把变量sumError声明为0在开头，然后你添加错误从输出，然后在隐藏图层的for循环中它再次添加到sumSquaredError变量，但是如果你要计算训练的错误，为什么它在“隐藏层cucle”里面？ / p>

for(int l=totalLayer-2;l>0;l--){ 
    for(int j=1;j<NeuralLayers[l].getTotalNode();j++){

    }
    updateWeight(learningRateTemp,momentum);
    sumSquaredError+=sumError;
}

不应该在外面吗？

我会参考之前回复过我的人的伪代码。

link

希望这有帮助！

神经网络BackPropagation培训的错误减少太慢

1 个答案: